Fluid dynamic pressure bearing

Abstract

A cylindrical fluid dynamic pressure bearing includes: a shaft hole which has an inner peripheral surface and into which a shaft is inserted; plural separation grooves formed at equal intervals on the inner peripheral surface in a circumferential direction, the separation grooves extending in an axial direction and dividing the inner peripheral surface in the circumferential direction; and circular arc surfaces formed on the inner peripheral surface between the separation grooves, the circular arc surfaces being eccentric with respect to a center of an outer diameter of the bearing and being inwardly biased toward one circumferential direction, wherein the number of the separation grooves is 3 to 6, the number of the circular arc surfaces is the same as the number of the separation grooves, and the separation groove has a width corresponding to an angle of 8 to 20 degrees in the circumferential direction of which a center is an axial center of the bearing, and has a maximum depth of 0.05 to 0.15 mm.

Dependencies are inferred from the claim text.